This invention pertains to the art of grounding assemblies and, more particularly, to a grounding structure utilized with linear members such as overhead cables and the like.
The invention is particularly applicable to grounding a fiber optic cable and will be described with particular reference thereto. However, it will be appreciated that the application has broader applications and may be advantageously employed in connection with many other cable environments and uses.
Commonly assigned U.S. Pat. No. 3,539,139 to Eucker issued Nov. 10, 1970 illustrates and describes a conventional cable support assembly that effectively limits cable vibration and other dynamic cable motion. Briefly, a conductor cable is received between mating cushion members that grip the cable along a predetermined longitudinal segment thereof. Helical rods or wires encompass the cushioning member and extend axially beyond opposed ends of the cushion member to grip the cable. A two part, saddle-like member is received over the helical rods. The saddle-like member is likewise surrounded by a clamping strap interconnected with a suspension arm means through use of a fastening means such as a bolt.
The foregoing conventional support assembly has been widely used in suspending linear bodies such as electrical transmission lines or cable. With the recent advent of and increased emphasis on fiber optic technology, this support assembly is considered highly desirable since it virtually eliminates compression or crushing stresses on a protective aluminum member containing the fragile optical fibers. The elimination of compression stresses protects against unwanted signal loss.
In adapting the support assembly to fiber optic cable, a first set of structural reinforcing rods is wrapped around the fiber optic cable, more specifically around the protective aluminum member or other support structure protecting the individual optical fibers. Thereafter, the above-described support assembly is utilized in much the same manner as is the case for conventional electrical transmission lines or cables. The structural reinforcing rods prevent kinking or bending of the fiber optic cable during unbalanced longitudinal loading conditions. Kinking and bending is also considered undesirable since it may produce signal losses in the optical fibers which might not diminish thereafter when the unbalanced loading is reduced.
Typically, prior art arrangements were grounded through use of a clamp arrangement, the clamp was attached directly to the optical ground wire at an area beyond the ends of the helical rods of the support assembly. This exposed the optical ground wire to potential fatigue failure and also created compressive stresses at the clamping point.
Still another problem associated with fiber optic cables is the need to increase or enhance current transfer to reduce the heat level associated with a high magnitude fault condition. The increased heat level has a deleterious effect on the optical components, thus necessitating an increase in current transfer.
The present invention contemplates a new and improved grounding mechanism which overcomes the above-referenced problems and others, and provides a simple, easily installed grounding arrangement.